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The biggest issue I see happening is, we've used up all of the "easy resources" on the planet. So if for some reason we have some kind of global conflict that significantly sets back civilization/technology, we may lose our chance of ever exploring space.

Trying to rebuild our industrial technology back up from scratch when the required resources are gone, require advanced processing, or the rest is now 5 miles deep; might make it impossible in any meaningful timeframe.

We haven't created or destroyed any elements. We just use them, or modify the chemicals they are in. If we need them (and have dug them all up), we can't mine them from the ground, but we can mine them from the landfills and buildings, like some are doing with copper now. Materials are more easy, not less easy.

Helium is "manufactured" by radioactive decay underground. Also, He is unnecessary for life. You only need it if you want a funny voice, or poor lift from something less flammable than H. Aside from some uses as a coolant, we wouldn't lose much if there was no He left.

Helium has a lot more uses that you seem to understand. Particularly as a superconductor (not a coolant). Without it there would be no high field MRI scanners. As far as I know, there are not permanent magnet MRI scanners above.3T. The standard MRI in hospitals are 1.5T and 3T are becoming very common. These both require He. The 3T magnets use a lot of it. Particle accelerators need He, as do mag-Lev trains, rail-guns, etc. Obviously these aren't things that mankind can't live without. But unless we can find a suitable replacement to use as a superconductor, it will set back a lot of science and other advances.

It cools the target superconducting material enough so that it becomes superconducting, can carry lots more current and thus create the high magnetic field without losing its superconductivity: https://en.wikipedia.org/wiki/... [wikipedia.org]

Helium has a lot more uses that you seem to understand. Particularly as a superconductor (not a coolant).

Cold superconductors are often just at the boiling temperature of He, so liquid He is the best way to regulate temperature for "old" cold superconductors. It is not a superconductor, but is currently is used for many (nearly all?) commercial superconducting equipment.

I fully understand the uses and needs for it, as I explicitly said "coolant" just because I figured someone would come up with the complaint you had, though I didn't expect them (you) to correct so incorrectly. Someone else already pointed o

The problem is that getting those elements back requires energy in most cases. The exact elements that the grand parent was referring to are the ones that allow us to get started producing energy with which to do useful things. Sure, all the elements for oil still exist, but the actual oil doesn't, and to get the oil, we need energy.

Hydro, wind, and chemical (all used long before industrialization, windmills, water wheels, wood fires). And once you make a panel, you use it to make more.

Seems pretty obvious. Fire was the first means of harnessing solar panel, why have you forgotten it? Mills using water and wind have been around for 2000+ years. We still have hydro and wind, just generating electrical power, rather than being used directly for mechanical advantage.

You are half-right. Far more coal remains in the ground than has been mined,

That's considerably more debatable than you make it sound. I was reading an article a couple of years ago in my trade journal ("GeoScientist [geolsoc.org.uk]" ; there's a hint there), which suggested that we're already something like half way through our exploitable reserves of coal.

Actually any follow on civilization would find vast quantities of highly processed resources all over the place, locations we currently call cities. Even a widespread nuclear war would still leave large amounts of steel, copper and aluminum sitting around for exploitation.

Yes, just like Hiroshima and Nagasaki are radioactive hell holes. Unless we're using dirty bombs, most cities/ruins will be completely safe 10-20 years after the balloon goes up. Plus, not every city will be nuked

Facts for you nuke hysteria types: So far, over two *thousand* nukes have been set off. On the ground. Over 500 in the atmosphere alone. In space. Under water. On the water. Underground. And, newsflash: No continents were lost. Many of these nukes were of considerable size; the Soviets had the record at 50 megatons in one shot, but that's not to say others weren't trying. Total nukage set off so far, about 600 megatons (conservatively.)

Face it: Nukes surely do make big bangs compared to conventional explosives, and blown open power plants tend to make good sized parks as everyone runs screaming (although note the wildlife seems to do ok, all things considered), but in reality, nothing much significant happens consequent to a single actual nuke or power plant failure. Certainly not in proportion to civilization in general. And certainly not at the scale of continents.

Another fact: There's more crap in the air you should be worried about from burning coal than there is from all man made nuclear activity, ever.

I agree with all your points, but you completely fail to address the parent's concern.

Yes, under normal operation nuclear plant vents far less radioactive material than a comparable coal plant. But they also pretty much all have at least several years worth of spent fuel lying around "cooling" enough to be safe to transport to long-term storage facilities, often within the same building as the reactor. Hit that building with a nuclear weapon and you vaporize all waste, plus the fuel still in the reactor -

Agreed. Just look at the progression of so called civilization. The US's economy is becoming more and more of a service economy. Entertainment is becoming a larger and larger fraction of the GDP. I don't see how a species can hope to survive the next catastrophe when people are more interested in living hedonistic lives. As soon as people start to really feel the pressure of finite resources, war and eventual nuclear holocaust seem inevitable. It wouldn't take very many H-bombs to screw up the global climat

Yep, them's the breaks. A friend of mine says that Ice Ages are God's way of saying "Next!" - wipe the slate, bring in somebody new.:) I completely disagree with the guilt-reasoning of many environmentalists. That's a matter of values, which imply a belief system. To stick strictly with the pure evolutionary model, you can not say whether what humans do is "good" or "bad" for the Earth, only whether it's successful by some practical measure. IOW, if we "destroy the Earth", by which is generally meant,

If I break both your legs that is neither good nor bad for you as your legs will get better and good and bad is an alien concept to legs, "Next" you will cry immediately afterwards, just as you would after the next guy in line punched you in the nuts.

In a mere couple of thousand years we've managed to move from "indoor plumbing lolwut" for most of the planet to space flight and fast cheap intercontinental travel. I'd say we're doing pretty well.

As for the great filter, one need only look at the number of mass extinctions that have occurred naturally. Even should the conditions for life as we know it be relatively common (as in life capable of interstellar exploration, not just subsisting under fifty kilometers of ice), the odds of intelligent life arising might be a tiny fraction of that. There could be an enormous array of variables in play, maybe local galactic conditions have only recently matured sufficiently to allow life to exist. Maybe we could simply be freak occurrences. Maybe nobody has managed to figure out FTL travel and they'll get round to us in a few millennia. Maybe nobody's got listening posts within the couple of light years it takes for our radio noise to peter out.

Am I saying the Drake Equation is almost certainly full of shit? Why yes I am.

You're far too kind. By the way the human race is behaving currently, we don't deserve to get off this dirtball anytime soon. For fuck's sake, look at us! We hurt and kill each other for stupid reasons. We have entire cultures that consider women (and others!) to be less than a human being. We have assholes who attack, seriously (and profoundly!) injure and kill little girls because they have the audacity to want to learn how to read and write. We haven't proven we can adequately care for the environment of

There seems to be more overall effort into the obstruction of further progress, than to encourage it.

If we don't get off the planet, there will be an extinction eventually; either an asteroid or a "terrible mistake".

Either way, dispersal is really the only option in the long run.

If it weren't for the politicians, we would have had more moon missions, and the Shuttle wouldn't have turned out to be the clusterfuck it turned out to be.(If you were along for the ride, the shuttle program was supposed to be comp

Government is the problem, not Capitalism. The moment government gets involved, people get paid off to fuck with the system in such a way that it because a good old boys club. Unrestrained Capitalism has its own problems as well, but those are solved simply by time in most cases. It is patience that is lacking because government only reacts to the "We must do something, this is something, therefore we must do it" tyranny. Nobody stops long enough to ask "why" we must do something.

It's not really government per se that is the problem, it's concentration of power. Concentration of power pretty much always leads to bad outcomes, be it in the public sphere or private. So as it turns out the conservatives are right, big government is bad, but it also turns out the liberals are right, big corporations are bad. Sadly, they're both too busy arguing to figure out that they agree on the underlying principle.

"Big corps are about 0.1% of the problem big governments are. Based on megadeaths in the 20th century."

Without predatory capitalistic corporations which -literally- feed their children on the human misery that is receiving healthcare in the us, america would have universal healthcare. Lobbyists. One of the reasons that the parent comment is right and that all the ills of governement are indeed caused by corporations! (paraphrasing what im sure he meant:P)

That is an incredibly complicated thing to determine, and is certainly not one-sided like you make it seem. In the 20th century, over a billion people died prematurely due to smoking for example. That's about ten times more people than in every 20th century war combined. Approximately two million people die from occupational hazards each year? How much of that is preventable?

Really? Let's take social security. It would be okay if Grandma came and lived with you, right? Her meds are a bit on the expensive side but as you say, time will solve the problem...one way or another.

How about clean air and water? It took the EPA cracking the whip before the U.S. made an attempt to fix the problem. Of course capitalism and time would have solved the problem....eventually...maybe when no life could survive any longer.

Maybe we should let the FDA get out of the way and allow Joe's Bait and

If you're going to argue that the DARPA protocols informing the Internet are some kind of anti-capitalist triumph, fine. Keep in mind that you also just bought the Military-Industrial Complex and all of the wars the U.S. has fought. So ya got a lot of artillery and missiles goin' for ya.

I think I'll beg to differ, at least on the first sentence, at least on a matter of scale and influence. The second one is what I would term an 'issue in progress' - we won't really know the outcome for another five or ten years. Recognize that both sides of that question are corporate, so the sparring will continue for a long time.

I first used the Internet in the late 1970s and early 1980s, as I worked at companies that had DoD or research connections. At that time it was essentially email and file transfer, and it's quite possible that without commercial creativity, it might still be stuck there. Sorry this is long and digressional, but I enjoyed writing it, so there.:)

I acquired my first domain name in 1991, before the WorldWideWeb program - the program by Tim Berners-Lee, which ran on and was inspired by the NextStep system. Every program on the NeXT was capable of incorporating any form of media, including email with video and voice snippets, etc. WorldWideWeb fit right into the other similar programs on the NeXT - his real achievement was conceiving of the HTML language, which allowed (in theory) other computer systems to support similar capabilities. NeXT itself was inspired by SmallTalk, the Xerox Alto, and lessons learned in the Macintosh. Almost all of the above was done in commercial and academic research settings. Lee's own work was somewhat outside CERN's "real" purpose, and was allowed rather than driven by CERN - the closest thing to a government that I've mentioned. So nearly all of this was work being done for mostly commercial reasons (just as IBM Labs, Xerox PARC, and ATT Labs were commercial projects), but lived on top of the fairly mundane (from our point of view, today) vision funded by DARPA to ease data transfer between big mainframes at research facilities in support of rather vague defense related goals.

IMHO, without the commercial creativity and openness to finding new ways to get an advantage by improving the Internet, SendMail would be a lot simpler because it would still only support the two or three earliest mail protocols - it's possible that not even SMTP would have been invented, to clean up the email protocol problem. Government, in the form of DARPA, took the essential step of deciding to connect things together - this is a classic infrastructure initiative. And Al Gore, bless his little heart, did sponsor the bill to allow commercial use of the Internet. Before that, from my own experience, using the net was not easy, and having an actual presence on the net was hard and expensive. Getting a connection through some other company (see the history of UseNet) took weeks, and probably money - a 56Kbit line cost IIRC over $100/month in 1981 and a T-1 (1Mbit/s) was about $1500/month unless my memory fails me, plus you had to pay whoever you were connecting to. Getting a domain name took weeks after that, and depended on one guy, Jon Postel (RIP), to update his manually maintained list.

Nearly everything you know about the modern net, every protocol commonly used, every feature you depend on, is the result of capitalist innovation, not government projects. And I think this is a good example of how government and business - and not least academia and creative individuals (often with $ in their eyes) can each do what they do best. Some folks disagree but I think government is generally pretty good at building and maintaining highways, and providing the regulatory infrastructure that allows businesses to compete evenly without a race to the unsafe and dastardly bottom. And businesses, if not _too_ large, both benefits from that and provides the creative fluidity that makes things better. (From my view of systems theory, IMHO any market where any business has control of over about 20% of the market, and all but one have less than 12% or so, is essentially frozen and non-competitive. But that's another topic.) Neither is perfect, but over time I think we continue to converge toward a better situation - and whining about the problems is one of the most important factors in pushing that progress.

Oh Yeah? Well in the 1970's and 80's I was using BBSs. Without any government or corporations we organized an email system called Fidonet because the design by committee ARPANET was taking too damn long. We used "best effort" packet routing too, store and forward via overlapping local calling areas.

Now NASA has finally gotten on board and is working on protocols for the Space Internet: Delay Tolerant Networking -- Store and Forward. For the past 25 years we have had the technology to never have service fees for our online wireless data, but it is prevented because commercial interests would rather charge $1,638.00 per megabyte of text messages. You could buy your transceiver, and join the mesh. Bigger cache and antenna, faster connection. Point to point links could be organized by community ran non-profits just like Fidonet was (and still is ran in 3rd world countries, because your "commercial" and "government" interests don't give a damn about brown people). The more people downloading a resource? The MORE AVAILABLE it is -- No congestion issues. No "Slashdot Effect".

The Internet is a nice design but it wasn't the only game in town. Were it not for long distance fees and government oppression of wireless spectrum the Internet might never have come to be, and no one would be paying hundreds of dollars a month and getting bandwidth capped and overage charges and increased fees, AND content-provider protection racketed (see Netflix v Comcast "fast lane" BS). Bits are actually getting cheaper now than ever before, and the price they charge is increasing. The Web of Data Silohs is fucking moronic, and the folks who designed the centralized web were far from geniuses. [youtube.com] I have a whole garage full of innovative equipment that can revolutionize the way we use data: A Distributed File System (originally designed for the wireless mesh) and cross platform OS made from scratch to utilize the decentralized Internet / mesh to its fullest. Guess what? I'm scared to even show anyone because the corporate anti-competitive patent trolls.

The Internet's days are numbered. Store and forward means no spying on your browsing. The idea that a piece of "data" resides at a "URL" on a "Server" is fucking stupid. "Files" are just human readable names linked to a hash-code, on ZFS and BTRFS as it art in Bittorrent. The info hash can prevent link rot. "Websites" are unnecessary bottlenecks. Sign your content with your PGP key and let everyone have it, we never needed a centralized server system. The w

One, they got to the moon even faster with Communism! Nobody ever invented fire for the first time in 200 years. That's a ridiculous argument.

Two, I don't know on what basis you claim capitalism started 200 years ago. In what sense was the Roman empire not capitalistic? Or the "barbarians" that opposed the Roman Empire? The Phoenicians are infamous ancient traders.

Millions of races could have (and probably did) come into existence and gone extinct since the beginning of the Universe. Life on Earth has only been able to do more than look up at the stars for an extremely short time.

Because they aren't possible? becasue they have populated the other half of the galaxy? becasue they don't need to grow that fast? becasue they have all been wiped out be a variety of event. Specifically wiped out faster then they can be built?

It's like getting a thimble of water from the ocean and asking "where are all the fish?"

one tenth lightspeed is not slow at all, and in fact more likely to get a vessel destroyed as contact with the smallest pebble would be disaster. And Von Neumon starships have even more obstacles to their existence than life itself; it's one thing to have a creature with muscles and digestive system, another for a machine with a fusion motor in its butt needing tons of helium-3 or deuterium

My theory on it is a bit different: If you posit that travel is indeed restricted to 'slow' speeds, IE 1-2% of light speed, and that habitable planets are rare enough that they're quite far apart, you run into that travel between solar systems with habitable planets can take sufficient time for significant amounts of evolution to take place.

Summary: By the time the generation ship manages to reach the new system, it's significantly likely to have evolved to be more suited to live in space, not a planet. At which point it concentrates on colonizing the asteroid belt and such, not bothering with the planet that so interested their ancestors.

Alternatively: We're becoming more and more concerned with conservation today. If this is a common function of intelligent life, our system could have been identified as a potential life-evolving one millions and millions of years ago and declared a nature preserve or something, in the hope that something like us would evolve.

I agree with your logic as far as the nature of star populations goes, but there's been advanced land-based life on Earth for close to a billion* years. Dinosaurs kept mammals down for more than a third of a billion before we got a chance. Unless you're also arguing that intelligent life will necessarily require the same sort of treatment on any other planet, it seems like there's easily hundreds of millions of years where some intelligent variation of dinosaur could have evolved instead. Even if one of the

Our one example hasn't really been around for very long though, all estimates of the Sun's life cycle indicates Earth should remain habitable for another billion years or more. Where were we even a thousand years ago? It doesn't matter if the technology isn't ready until 3014, it's still a blink of an eye on the time scales we're talking here. And there's already semi-realistic craft designs like Project Orion that'll take hundreds of years to reach the next star, not tens of thousands. Unless the world goe

Yes but many of those earlier stars and solar systems didn't have the same complexity of elementswhich may be necessary for life. It's possible only 3rd or 4th generation stars, etc... support life.I also read recently that someone calculated the age of our dna based on a certain metricand their number came out older than earth's age. If this is true then it gives credibility to thepanspermia theory. Another interesting observation based on the big bang is that the universe wentthru a brief period of tim

Ours is not one of the early-generation stars, but life as we know it requires some trace heavy metals, so complex organism require later generation stars (so that the older stars can generate heavy elements and nova them out). So we are a young system, but could be the oldest capable of life as we know it.

If Kepler-186f is teeming with intelligent life, then that would be really bad news for humanity because it would push back the Great Filter’s position further into the technological stages of a civilization’s development. This would imply that catastrophe awaits both us and our extraterrestrial companions.

No it wouldn't, because then Fermi's Paradox is solved - Fermi's Paradox exists because we Earthicans are, by all appearances thus far, the only life that exists, intelligent or otherwise. If the first exoplanet we manage to check harbors intelligent life, then it would suggest that there is a lot of intelligent life out there, and it is just effing hard to communicate and travel over interstellar distances.

It wouldn't change the paradox at all. It would just strengthen the idea of the "great filter" or whatever, that basically states the *reason* for the paradox isn't because we are unique. Instead, the reason is because something filters out practically every species before they are able to colonize past their planet. So if Kepler-186f were to be "teeming with intelligent life" then we'd most likely be observing them before they have been filtered out (killed off) by something.

A civilization would be quite hard to detect. The best chance is probably radio emissions, but even that has a fairly short practical limit. And it's noteworthy that our emissions are dropping today, as we increasinly use the spectrum for low-power digital systems rather than analogue "scream at the top of your lungs" broadcasts. It wouldn't be too far-fetched to imagine that we'd be effectively silent in another couple of generations, as we push toward more effective transmission technologies.

Most of our energy right now comes from old stores of energy which we have been extremely lucky to find, and which will either run out, or become too dangerous to use due to resource exhaustion.

Our behaviour can not cope without scarcity. Look at Australian aboriginal people. Placed in an environment with relatively low scarcity, their culture collapsed. In the next hundred years automation will push large parts of our populations out of work. There will still be food and shelter for them, but will those pe

Nonsense. People often become nonviolent in societies that one, have adequate amounts of food, two, have adequate amounts of water, and three perceive themselves as isolated from attack. For example, the Tahitian men, the Minoan men on Crete, and the Central Malaysian Semai were nonviolent during the period in their history when all three of these conditions prevailed.

The basic problem with the Fermi Paradox is this, we don't really have a technology we ourselves would reliably use to communicate between stars, thus the fact that we can't find alien civilizations using a technology we wouldn't use proves nothing. Arguably the whole radio search is a waste of time since we have no reason to believe we will find anything, indeed we have one reason to believe we won't! For all we know, there could be lots of miniature alien probes all over our solar system right now, or maybe they communicate with wormholes, or it is impractical to communicate long distances, or who knows?
Basically, we really don't even know what we are looking for in the first place, so the Paradox falls on it's face for lack of information.

Not to mention that even if they were in the solar system they wouldn't necessarily be in a form we'd recognise as life. The premise of the Fermi Paradox seems very simplistic to me, as if aliens would just turn up in flying saucers and be humanoids. You only need to look at how diverse life is on one single planet to imagine how utterly different an alien could be to us.

It's not about communicating with other civilizations, or even about directly observing them. Life could very well be different from us, but unless it thrives in dark matter, we should be able to observe the side effects of any civilization that has had enough time to explore the galaxy. Stuff like dyson spheres, etc.. More importantly, any such civilization would have eventually come to our little neighborhood and done things like harvest out planets.

??? What are we looking for exactly? What effects on the galaxy do you mean? Why would they harvest our planet, to take the materials where exactly and at what cost?
This is my point, we don't event understand what we are looking for.

There's about 5,000 years of recorded human history. But there's only about 200 years of industrial civilization. It's been just about 200 years since the first time a paying customer got on a train and went someplace. Think of that as the beginning of large-scale deployment of powered technology.

It wasn't until the middle of the 20th century that human activities started making a big dent in planetary resources. By now, we've extracted and used most of the easy-to-get resources. There's argument over how long it will take to run through what's left, but it's not centuries, and certainly not millennia. More difficult and sparser resources can be extracted, but that's a diminishing-returns thing.

It's quite possible that high-power technological civilization only has a lifespan of a few hundred years before the planet is used up. We might be saved by the Next Big Thing in high-power technology, but there hasn't been a major new energy source in 50 years. Nobody can get fusion to work, and fission is riskier than expected.

Which is why space travel is important, especially colonization. Think of it this way: a herd of animals lives in an area with plenty of food and water. Now, after a while, the food and water starts to dry up. Does the herd just sit around and wait to die, or does it venture out into other areas, expanding its territory. Essentially it is a natural process, and the only hope humanity has of any significantly long term existence.

We've seen fossils of simple (prokaryotic, bacterial) life that are at least 3.8 billion years old. Basically the instant it became possible for single-cell life to exist, it did. That suggests that simple life is *easy*.

It took evolution roughly a billion years to produce eukaryotic life, suggesting that step is hard. It also took 2 billion more years to produce a eukaryotic lifeform capable of space flight, suggesting that step is also hard.

The sun is predicted to make life on earth impossible in roughly ~1 billion years. An oops anywhere earlier in the process, and evolution wouldn't have had time to recover. We're lucky to exist.

So my suspicion is that the universe is relatively teeming with simple life anywhere it is possible (there are tentative signs that there *might* be life on Mars and possibly Titan too) but complex life is much rarer, rare enough that it's not surprised we haven't found any yet.

Also, wanting to communicate and explore is inherently a human desire, and whatever neo-human-cyber-whatever descendants emerge from the Singularity might not have the same desires. And I can predict their desires much more accurately than I could an aliens.

We've seen fossils of simple (prokaryotic, bacterial) life that are at least 3.8 billion years old. Basically the instant it became possible for single-cell life to exist, it did. That suggests that simple life is *easy*.

It took evolution roughly a billion years to produce eukaryotic life, suggesting that step is hard. It also took 2 billion more years to produce a eukaryotic lifeform capable of space flight, suggesting that step is also hard.

Since we only have one data point, all of this is basically a guess though. Maybe it doesn't take a billion years to produce eukaryotic life - maybe it's really quite fast, but the conditions just weren't right for a long time and that held it back. Get another planet with more suitable conditions and you might be talking millions instead of billions of years. My point is that we just don't know because we don't have enough data to tell the difference between low probability and high probability events.

The core of the Fermi Paradox is that there does not appear to be any basic physical limitation that would prevent an intelligent civilization from colonizing the entire galaxy in much less than a 100 million years - yet there is no case that can yet be made that Earth is anything like a boundary case of the "earliest possible biosphere". It is not a solution to the Fermi Paradox to postulate reasons why one intelligent species or another might fail to do so, it has to apply to every one of them since one outlier would go on to colonize the galaxy.

I think part of the resolution of the paradox is the implicit notion common to us humans that our form of tool-using symbolic-communicating intelligence is some sense "inevitable" and will arise given enough time. Yet observing the evolution of the large animals on Earth does not give any reason for thinking this is some sort of normal progression. The Great Apes, very similar to hominids, have not shown any trend toward evolving larger brains since the hominid-ape split 7 million years ago. No general trend toward developing human style intelligence is evident anywhere. The emerging story of hominid development is that a long series of lucky accidents seems to have been necessary to bring it about.

Even if the "Great Filter" exists; even if it were 99.999% effective at wiping out civilizations, that would still mean there have been billions of years, for billions of civilizations to arise, and of those billions, perhaps tens of thousands survived to colonize space.

If you read about the "great filter" then you'd find out that the big question isn't what that filter is, but WHERE it takes place. Is it the step from single-cell to multi-cell organism? Is it the rise of special intelligence? Part of the warning with the great filter idea, is that since there seems to be no observable evidence (directly or indirectly) of any other species progressing past the point we are at, it stands to reason that the "filter" could in fact be very close at hand, either through some social thing like nuclear war, or something else like a nearby exploding supernova.

So either we have already passed the filter in one of the many earlier stages in our history, or it is yet to come. If it's yet to come, that's something we should be concerned about.

In good sci-fi literature we see this come up again and again in many hypothetical scenarios. Ian Douglas answers the Fermi Paradox by positing a future where a galaxy-spanning race of hyper-darwinist xenophobes mercilessly wipe out any space faring "other" race much to humanity's horror when they stumble across ruins, relics, and artifacts left by other races.

In the Crystal Spheres by David Brin we see a future where all intelligent life is closed off from habitable worlds until they themselves become space faring, and humanity is among the first to reach the stars.

In To Outlive Eternity by Poul Anderson we see a possible scenario in which humans are first by design.

Peter F. Hamilton takes us through another possibility in the Night's Dawn Trilogy where intelligent life is fairly rare and what there is out there doesn't really have an interest in "lesser" forms.

In all, we won't know for sure for a long while yet, but I think there are some good possibilities out there. And until we actually do make contact or prove ourselves to be alone, good sci-fi keeps us company in the meantime =)

How unlikely is it really, on a cosmic scale, to have a large Luna-like moon and Earth-like axial tilt?

Well, if you start with a list of the list of large (say, over 1000-km diameter) planets and their moons [wikipedia.org] in our solar system, you'd expect such things to be fairly common. All the planets larger than ours have such big, round moons, and little Pluto has one with a 1200-km diameter. Uranus has an extreme axial tilt; all the rest are within 30 degrees of perpendicular to the system's plane. (Venus is a bit odd, though, since it rotates so slowly that it's usually listed as "retrograde", with the south pol

That's an interesting alternate God. Most conceptions of singular-God that I'm familiar with have him as a creative force, not a destructive force actively eliminating all life in the universe that does not lead to humans on Earth, like a cosmic bansai bush cultivator.

We deserves life, and the stars.we crawled out of the ocean, we got out of the trees, we defeated every predator, we built towers of glass and steel, we have spanned great water ways, we have been to the moon, and we have a machine out side out solar system

We surely DO DESERVE the stars.The stars are no place for pansies, quitters. The stars are for whom ever can grab them.

People content to live in a squalor with no motivation or goals, no curiosity, those subhumans done't deserve the stars.

Death is what we deserve, and if we do not change, death is what should be for every man woman and child on this earth.

Don't worry, that is what every human, and every other living being, will get at some point. Even if we somehow get to the singularity and human minds can be implanted into machines (philosophically can we even be called human at that point anymore?) the heat death or collapse of the universe will destroy everything eventually anyway. And if anything ever counteracts human nature (you can't change it, but you can affect it), it would be spacetravel and contact with another intelligent civilization.

There is some truth to this. I worry what happens when personal spacecrafts are available.We are slowly "civilizing" the planet. Slave labor, pirates, etc.. are somewhat rare.What happens when you can kidnap someone and create a slave camp on a random planetmillions of miles away? I hope we develop AI and other technologies first so that we canprevent ourself from regressing once there are places to hide again.

This is completely absurd. There are roughly 7 BILLION people on this planet that you insist on painting with the same brush in the same stroke. And that counts nothing towards the countless other humans that have gotten us to this point in our evolution. Yes, humanity at its extreme can be a toxic parasite on its environment and fellow man; however that totally disregards the ability of the capable to rise above the morass and drag the bottom up with it. Don't think that's how this story will end? You thin

While they would probably still be using radio waves, or at least EM radiation of some kind, for communication, they might be using them in such a way that we wouldn't be able to pick them up. For example, they might be using highly directional communications and spread spectrum signals carrying complex communications protocols that look like noise if you don't know exactly how to read them. That's not particularly far-fetched since that's what most of our telecommunications consist of now.